CSS 3 Module <== Test # ==>
W3C Selectors 31 of 276 of the static tests category
Testing Date Revision
:root pseudo-class (ID #27) 2001-07-11 1.0

The background of the document should be green

html { background-color : red }
*:root { background-color: lime }
<p>The background of the document should be green</p>